Data storage systems interact with media libraries in data storage and retrieval operations. Media libraries house and control physical media (magnetic tapes, optical disks, and so on) that is used during storage operations, such as data backup operations. Libraries are limited in the number of media components they are able to hold, in many cases due to the physical size of the library. Therefore, a data storage system may need to transfer media components out of the library that are no longer needed or useful for data storage (e.g., media components at their storage capacity, or media components scheduled for offsite archiving), and bring in new media components for future storage operations.
Data storage systems may employ management systems to track the movement of media components to and from media libraries. Periodically, the systems transfer “full” or other media components to off site storage locations. Management systems may track the movement or location of media components used by a data storage system.
The management systems typically rely on policies that instruct the management systems as to the location of media components and the time at which to transfer media components to a determined location. However, the policies may be somewhat inflexible and lack insight into the needs of a data storage system or its policies, and therefore may instruct the library to perform undesirable media component transfers.
Additionally, libraries may look to similarly rigid policies when ordering new media components to be used in the system. Again, typical data storage systems, using rigid media component ordering and buying policies, typically do not achieve an optimum balance between the needs of a system and the number of media components coming into the system to meet those needs. Some media components are expensive, and thus ordering too many can be costly. Alternatively, it can be detrimental to the system if too few media components are available for a given storage operation job.
Furthermore, media management systems are not able to control all aspects of media component transfers. Media components are likely to be transferred to off site storage locations operated by other entities than an entity operating the data storage systems and media libraries. Also, media components are purchased from outside vendors. Therefore, the management of media components may stop or be severely limited once media components are not physically within or controlled by the system.
Some types of media, such as removable Universal Serial Bus (USB) drives, may be difficult to uniquely identify. For example, many USB drives do not contain a serial number or other identifier. Such media may also require additional human management. For example, unlike tape libraries, robotic systems for moving, loading, and tracking USB media are not generally available.
The foregoing examples of some existing limitations are intended to be illustrative and not exclusive. Other limitations will become apparent to those of skill in the art upon a reading of the Detailed Description below.
These and other problems exist with respect to media management systems.
In the drawings, the same reference numbers and acronyms identify elements or acts with the same or similar functionality for ease of understanding and convenience. To easily identify the discussion of any particular element or act, the most significant digit or digits in a reference number refer to the Figure number in which that element is first introduced (e.g., element 110 is first introduced and discussed with respect to FIG. 1).